Unanswered: tree store append child

Unanswered: tree store append child

I populate a tree panel with a static treeStore that not have a specific model or reader(i don't need server to populate the store becauce i populate dynamicly).when i try to append child to the root for example with this syntax:
expressionsStore.getRootNode().appendChild({ leaf:false,
text:'hello',
name:'test',
param:'param3',
isParam:true
})
the node is added but the raw property of the childNode is undifined and i can't access to the property 'param' for example.Any body has an idea to resolve this problem?thx